Question

A shell of mass 10 kg is fired from a gun of mass 500 kg The gun recoils with a velocity of 5 m/s. Find the muzzle velocity of the shell.

Answer 1

Since no external force acts on the gun-shell system, the momentum of the system will remain conserved.
MV = mv
$\Rightarrow 500\times 5=10\times v$
$\Rightarrow v=250m/s$